From mboxrd@z Thu Jan 1 00:00:00 1970 From: Artem Bityutskiy Subject: Re: [ANNOUNCE] util-linux-ng v2.17 (stable) Date: Mon, 11 Jan 2010 21:17:28 +0200 Message-ID: <1263237448.30988.31.camel@localhost.localdomain> References: <20100108093302.GS1969@nb.net.home> <4B47A713.9060405@zytor.com> <20100111140255.GA1416@ucw.cz> Reply-To: dedekind1-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "H. Peter Anvin" , Karel Zak , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, util-linux-ng-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Pavel Machek Return-path: In-Reply-To: <20100111140255.GA1416-+ZI9xUNit7I@public.gmane.org> Sender: util-linux-ng-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Mon, 2010-01-11 at 15:05 +0100, Pavel Machek wrote: > On Fri 2010-01-08 13:43:47, H. Peter Anvin wrote: > > On 01/08/2010 01:33 AM, Karel Zak wrote: > > >=20 > > > fdisk: > > > - the fdisk command aligns newly created partitions to minimum= _io_size > > > boundary ("minimum_io_size" is physical sector size or strip= e chunk > > > size on RAIDs). > > >=20 > > > - the fdisk command supports disks with alignment_offset now. > > >=20 > >=20 > > I think we should align, by default, much more aggressively than th= at -- > > because frequently we just don't know what the real physical alignm= ent > > is (think of flash media, which uses large erase blocks underneath.= ) >=20 > Flash has special mapping layer, and does not care (SD/MMC), or is a > raw nand and can't be used as block device (smartmedia). MMC does care, and we measured it, non-4KiB aligned writes were noticeably slower on real eMMC and some MMC cards. I cannot remember th= e numbers, but I vaguely recall something like 11%. So the first statement is incorrect. It really does matter. E.g., we observed that FAT FS was slower if the partition did not start from 4Ki= B boundary. --=20 Best Regards, Artem Bityutskiy (=D0=90=D1=80=D1=82=D1=91=D0=BC =D0=91=D0=B8=D1=82=D1=8E= =D1=86=D0=BA=D0=B8=D0=B9) -- To unsubscribe from this list: send the line "unsubscribe util-linux-ng= " in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html